tbuckley/cabot-search huggingface dataset:
MODL-19. CREATION OF AN IN VITRO MODEL SYSTEM FOR THE STUDY OF H3.1K27M DMG
Authors: Joseph Lagas, Lihua Yang, Oren Becher, Joshua Rubin
Journal: Neuro-Oncology (2022)

Abstract Diffuse Midline Gliomas (DMG) are a devastating group of pediatric high-grade gliomas that occur in the brainstem with a median survival of less than 1 year. A greater understanding of the early tumorigenic events is essential for the development of effective therapeutics. DMG is characterized by founder mutations in histone H3, either H3.1K27M or H3.3K27M. These mutations cause global hypomethylation, resulting in aberrant gene expression. It is unknown how this mechanism contributes to tumorigenesis. Interestingly, H3.1K27M DMG show an increased incidence in females, whereas H3.3K27M DMG shows no sex difference. This illustrates that the tumorigenic potential of H3.1K27M may be different between the sexes. Few models of DMG incorporate the study of H3.1K27M, even though it represents a unique opportunity to obtain valuable information on the tumorigenesis of DMG through the study of the sex difference. Additionally, an important regulatory element, a stem loop structure, present in mammals is missing from all previous models studying H3.1K27M. Thus, we have created an in vitro model system for H3.1K27M DMG that incorporates the stem loop structure utilizing the RCAS mouse model system. This system utilizes RCAS vectors and a RCAS-ntva transgenic mouse line to deliver specific mutations to nestin expressing cells in the brainstem, including neural and glial progenitor cells, the potential cells of origin. Confirmed through immunofluorescence staining, we can isolate a pure population of NPCs and transduce them with RCAS vectors in vitro to produce stable expression of H3.1K27M. Verified via immunocytochemistry and flow cytometry, delivering H3.1K27M with the stem loop included limits its expression to S phase of the cell cycle, mimicking the human disease biology. These results demonstrate that we have created an in vitro H3.1K27M DMG model system for the study of sex differences and tumorigenesis in DMG.
TMET-01. DISRUPTION OF THE SERINE-PRODUCING PATHWAYS SLOWS PROGRESSION OF THE SONIC HEDGEHOG-DRIVEN MEDULLOBLASTOMA
Authors: Andrey Tikunov, Dale Bates, Jeff Macdonald, Timothy Gershon
Journal: Neuro-Oncology (2022)

Abstract We have found that medulloblastoma metabolism is specialized to promote growth in the CNS and can be targeted for anti-tumor therapy. Prior studies show that serine is scarce in the CNS and that metastatic tumors require serine-producing enzymes to grow in the brain. We analyzed whether medulloblastoma, a primary brain tumor, showed similar serine dependency. We found that Sonic Hedgehog signaling, which induces proliferation in cerebellar granule neuron progenitors in normal development and medulloblastoma formation when hyperactivated, also induces PHGDH and SHMT1, which each catalyze key steps in different serine-production pathways. To define the functional role of PHGDH and SHMT1 in medulloblastomas, we bred mice genetically engineered to develop SHH medulloblastomas with mice carrying deletions of each of these genes. We found that mice with Phgdh-deleted medulloblastomas showed slower progression and longer survival times, compared to mice with Phgdh-intact medulloblastomas. Medulloblastomas with combined deletion of Phgdh and Shmt1 show even slower tumor progression. Stable-isotope flux analysis suggests that different serine-producing pathways compensate for the loss of individual serine-producing enzymes, providing a rationale for the greater anti-tumor effect of disrupting multiple serine-producing enzymes simultaneously. Our data show that serine-producing enzymes can be targeted as a novel approach to medulloblastoma therapy, and underscore the importance of targeting multiple serine-production pathways in complex metabolic interventions.
TMIC-64. EXTRACELLULAR VESICLE TRAFFICKING IN GBM
Authors: Cecile Maire, Amanda Salviano-Silva, Katharina Kolbe, Manfred Westphal, Katrin Lamszus, Franz Ricklefs
Journal: Neuro-Oncology (2022)

Abstract Extracellular vesicles (EVs) are secreted by all cell types, including tumor cells, and are found in increased numbers in the plasma of GBM patients. EVs may contain high-value genetic material that can be useful for tracking tumor development, as well as membrane proteins that affect other cells. This prompted us to investigate how tumor EVs might influence immune cells in glioma, and in primary and secondary lymphoid organs as well as in the circulation. To this end we used a syngeneic GBM mouse model and tracked tumor EVs from the brain to the meninges, cervical lymph nodes, plasma, bone marrow and spleen. Interestingly, we were able to identify tumor EVs mostly in the cervical lymph nodes by ImageStream imaging flow cytometry just 30min after tumor EV injection into the brain. However, when tumor EVs were produced by a large gliomas transfected with dTomato, we found them mainly in plasma, less frequently in bone marrow and never in the spleen. We confirmed these data by extracting DNA from EVs and detecting specific dTomato sequences using digital droplet PCR. In addition, we detected CD11b+ macrophages in the meninges that likely travel through the lymphatics that have taken up tumor EV or tumor material. We confirm that tumor EVs are capable of eliciting an immune response by activating T cells. However, prolonged contact and large number of EVs could also block antigen recognition by T cells and thus contribute to the propagation of an immunosuppressive environment in GBM.
BIOM-15. GLIOBLASTOMA CELLS SHOW ELEVATED CHITINASE 3-LIKE PROTEIN 1 GENE EXPRESSION IN RESPONSE TO HUMAN CEREBROSPINAL FLUID WITH INCREASED MIGRATION AND EPITHELIAL-MESENCHYMAL TRANSITION RELATED ACTIVITY
Authors: Lauren Whaley, Emily Norton, Victoria Corcino, Vanessa Jones, Kaisorn Chaichana, Alfredo Quiñones-Hinojosa, Hugo Guerrero-Cazares
Journal: Neuro-Oncology (2022)

Abstract Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults. GBM tumors proximal to the lateral ventricles have a worse prognosis with multifocality, recurrence, and lower overall survival. Studies suggest this increased aggressiveness is attributed to cerebrospinal fluid (CSF), as we have previously observed transcriptomic changes in GBM cells upon CSF exposure. GlioVis database reveals chitinase 3-like protein 1 (CHI3L1), a glycoprotein secreted by immune and cancer cells, is associated with poor prognosis and co-expressed with pro-inflammatory and tissue remodeling genes. We suggest exposure to CSF elevates CHI3L1 expression, consequently impacting malignancy-associated gene expression in patient-derived GBM lines. We first evaluated if patient CSF influences the expression of CHI3L1. GBM cells were treated with artificial CSF, non-cancer CSF, or cancer CSF for 72 hours. qPCR revealed significant increases in CHI3L1 (p&amp;lt; 0.0001), SPP1, and CD44 expression in cancer CSF groups compared to artificial CSF. CHI3L1 expression at the protein level is also increased by cancer CSF when profiled using Western Blot. Additionally, ELISA results indicated significantly higher levels of CHI3L1 in CSF samples obtained from patients with high-grade tumors compared to non-cancer samples. Next, we assessed if exogenous CHI3L1 stimulates GBM malignancy at the cellular level. An effective concentration of recombinant human CHI3L1 was determined through Alamar Blue assay, showing 500 ng/ml CHI3L1 increases viability in primary patient cell lines compared to non-treated media. Recombinant CHI3L1 also increases cell migration in Transwell assay. qPCR revealed Vimentin (p&amp;lt; 0.001) and Twist (p&amp;lt; 0.0001) expression significantly increases while E-cadherin (p&amp;lt; 0.001) significantly decreases in CHI3L1-treated groups, consistent with EMT and migratory activity. Ultimately, this study shows CHI3L1 is a CSF-induced factor in GBM and could be a therapeutic target as it enhances tumor malignancy by increasing proliferation, migration, and malignancy-promoting gene expression.
TMIC-61. LOSARTAN PREVENTS IMMUNOTHERAPY-ASSOCIATED EDEMA AND ENHANCES SURVIVAL IN GLIOBLASTOMA
Authors: Meenal Datta, Sampurna Chatterjee, Elizabeth Perez, Simon Gritsch, Sylvie Roberge, Mark Duquette, Ivy Chen, Kamila Naxerova, Ashwin Kumar, Mitrajit Ghosh, Kyrre Emblem, Rosa Ng, William Ho, Pragya Kumar, Shanmugarajan Krishnan, Xinyue Dong, Maria Speranza, Martha Neagu, David A Reardon, Arlene Sharpe, Gordon Freeman, Mario Suva, Lei Xu, Rakesh Jain
Journal: Neuro-Oncology (2022)

Abstract Immune checkpoint blockers (ICBs) have revolutionized the treatment of some solid cancers but have failed to benefit the majority of glioblastoma (GBM) patients. Two reasons underlying limited ICB benefit are: 1) immune-related adverse events, and 2) resistance conferred by the tumor microenvironment. Here, we show that ICBs induce cerebral edema in patients and GBM mouse models. This edema results from an inflammatory response to ICB treatment that disrupts the blood-tumor-barrier, as confirmed by intravital imaging, mechanistic blocking studies, and single-cell RNA sequencing. Losartan – a commonly prescribed antihypertensive agent – controls ICB-induced edema, reprograms the immunosuppressive tumor microenvironment, and improves survival under ICB therapy. In combination with a standard of care regimen in mice mimicking clinical treatment (surgical resection, chemoradiation), losartan increases the percent of long-term surviving (cured) mice under ICB therapy from 16% to 43%. Finally, a bihemispheric “resect-and-response” model to establish predictive biomarkers from the tumor microenvironment reveals that cured mice have an immunostimulatory (“hot”) immune tumor compartment prior to therapy. These results provide the basis for clinical testing of adding to losartan to ICB treatment for GBM patients.
TMIC-34. INVESTIGATING THE EFFECT OF IRON IN GLIOBLASTOMA CELL POLARIZATION AND MIGRATION
Authors: Ganesh Shenoy, Kondaiah Palsa, Quinn Wade, Chachrit Khunsriraksakul, Vladimir Khristov, Becky Slagle-Webb, Justin Lathia, Hong-Gang Wang, James Connor
Journal: Neuro-Oncology (2022)

Abstract Glioblastoma represents one of the most difficult-to-treat malignancies as evidenced by the poor prognosis associated with a diagnosis. The ability of glioblastoma cells to diffusely infiltrate into healthy brain tissue renders complete surgical resection challenging. Consequently, a large majority of glioblastoma patients end up with recurrent disease despite receiving maximally feasible surgical resection and rigorous chemoradiation. This work examined how modulation of cellular iron levels in T98G and LN229 glioblastoma cells impacted migratory capacity. Treatment of T98G or LN229 glioblastoma cells with iron in the form of ferric ammonium citrate (FAC) resulted in significantly reduced migration as assessed by time-lapse phase contrast imaging and wound healing assays. The iron-induced reduction in migration was able to be rescued by the addition of equimolar concentrations of deferoxamine, an iron chelator. Cellular proliferation in response to the iron treatments was quantified using both optical confluence and nucleic-acid-based proliferation assays and it was found that iron treatment at the concentrations used for the migration assays (0 – 300 µM FAC) did not result in reduced proliferation. Mechanistically probing iron’s impact on cell migration revealed that addition of iron resulted in decreased expression of Cdc42, a Rho GTPase that is essential to determining cellular polarity during migration. Functional cellular polarization assays further confirmed that reduced expression of Cdc42 corresponded to reduced cellular polarization. Bioinformatic analysis of CDC42 transcripts revealed the presence of potential iron-responsive-elements that may drive the iron-induced reduction in Cdc42 expression. This work highlights the importance of iron biology in impacting glioblastoma cell phenotype and potentially glioblastoma patient outcomes.
TMIC-78. CIRCADIAN REGULATOR CLOCK DRIVES IMMUNOSUPPRESSION IN GLIOBLASTOMA
Authors: Wenjing Xuan, Wen-Hao Hsu, Fatima Khan, Madeline Dunterman, Lizhi Pang, Derek Wainwright, Atique Ahmed, Amy Heimberger, Maciej Lesniak, Peiwen Chen
Journal: Neuro-Oncology (2022)

Abstract The symbiotic interactions between cancer stem cells and the tumor microenvironment (TME) are critical for tumor progression. However, the molecular mechanism underlying this symbiosis in glioblastoma (GBM) remains enigmatic. Here, we show that circadian locomotor output cycles kaput (CLOCK) and its heterodimeric partner brain and muscle ARNT-like 1 (BMAL1) in glioma stem cells (GSCs) drive immunosuppression in GBM. Integrated analyses of the data from transcriptome profiling, single-cell RNA sequencing, and TCGA datasets, coupled with functional studies, identified legumain (LGMN) as a direct transcriptional target of the CLOCK–BMAL1 complex in GSCs. Moreover, CLOCK-directed olfactomedin-like 3 (OLFML3) upregulates LGMN in GSCs via the hypoxia-inducible factor 1-alpha (HIF1A) signaling. Consequently, LGMN promotes microglial infiltration into the GBM TME via upregulating CD162, and polarizes infiltrating microglia towards an immune-suppressive phenotype. In GBM mouse models, inhibition of the CLOCK–OLFML3–HIF1A–LGMN–CD162 axis reduces intratumoral immune-suppressive microglia, increases CD8+ T cell infiltration, activation and cytotoxicity, and synergizes with anti-PD1 therapy. In human GBM, the CLOCK-regulated LGMN signaling correlates positively with microglial level and poor prognosis. Together, these findings uncover the CLOCK–OLFML3–HIF1A–LGMN axis as a molecular switch that controls microglial biology and immunosuppression, thus revealing potential new therapeutic targets for GBM patients.
NIMG-108. PHYSICAL STRESSES IN BRAIN TUMORS
Authors: Hadi Nia, Ashwin Kumar, Meenal Datta, Saeed Siri, Jeffrey McHugh, Gino Ferraro, Sampurna Chatterjee, Otto Rapalino, Bryan Choi, Brian Nahed, Rakesh Jain
Journal: Neuro-Oncology (2022)

Abstract Solid stress, distinct from fluid pressure, is a physical force contained in and transmitted by solid components of the brain tumor, including cells and the matrix they produce. Solid stress has been shown to promote tumor progression, and decrease anticancer therapy efficacy. This is especially relevant in brain tumors, as the rigid skull results in these trapped forces, increasing intracranial pressure, and potentially leading to other complications, including neuronal cell death. Here we present a novel method of quantifying these physical stresses in situ in both mice (glioblastoma [U87], brain metastasis [BT474], and ependymoma models) and patients. Briefly, following a craniotomy, mechanical forces that include solid stress are released, which causes the tissue to deform in peaks (areas under compression) and valleys (areas originally under tension). This tissue deformation is imaged via high-resolution ultrasound and analysed via custom MATLAB code to produce an accurate 3D model of the entire mouse brain, including the tumour region. For human samples, a pre-operative MRI is used to generate a detailed 3D model of the human brain. During surgery, the trapped physical stresses results in a bulge of the dura post craniotomy. We use BrainLab to measure the craniotomy induced brain deformation, which is then registered to the pre-operation MRI before being analysed in an identical fashion to the murine models using SolidWorks and Abaqus. We further show that in the brain metastases model, chemotherapy reduces compression stresses by 51%. Further, our technique results in fast processing time (~ 15 minutes), and has the potential to prevent the need for intraoperative MRI based on position simulations. As such, solid stress measurements provide a new class of mechanical biomarkers that can be correlated to clinical outcomes for predictive and prognostic value.
TMIC-60. THE ROLE OF ICAM1 IN GLIOBLASTOMA TUMORIGENESIS UNDER HYPOXIC CONDITIONS
Authors: Kaviya Devaraja, Olivia Singh, Sheila Mansouri, Hafsah Ali, Gelareh Zadeh
Journal: Neuro-Oncology (2022)

Abstract Glioblastoma (GBM) is a fatal brain cancer in adults with ineffective existing treatment methods. Cell adhesion molecules (CAMs) are proteins that are expressed on the surface of cells and enable them to interact with one another and the surrounding microenvironment. Intracellular adhesion molecule 1 (ICAM-1) is a cell adhesion molecule expressed by macrophages, tumor cells and endothelial cells in GBM. Preliminary data showed that ICAM-1 is associated with poorer overall and progression free survival in GBM patients and ICAM-1 expression levels increase in recurrent GBM tumors. TAMs enhance tumor growth and proliferation, within GBM. The goal of this study was to determine whether and how ICAM-1 expression on TAMs contributes to GBM tumorigenesis, specifically within the hypoxic tumor microenvironment. We hypothesized that ICAM1 facilitates TAM migration, proliferation and phagocytosis, thus enhancing tumor growth. We found that upon incubation of human and mouse primary macrophages in hypoxia, ICAM-1 expression levels increased and were further exasperated upon culturing with tumor cell-conditioned medium. Incubation of ICAM-1 deficient macrophages in hypoxia resulted in lower migration and proliferation in ICAM-1 deficient cells compared to wild type cells. When cultured with tumor cell condition media, migration and proliferation of ICAM-1 deficient macrophages was lower than wild type macrophages. Further, intracranial injection of tumor cells into ICAM-1 deficient and wild type mice revealed that ICAM1 deficient mice survived longer and had lower overall tumor volume than wild type mice. In conclusion, the expression of ICAM1 in TAMs likely promotes GBM tumorigenesis by enhancing their proliferation and migration into the tumor microenvironment. ICAM-1 plays a role in macrophage migration, proliferation, and its expression on TAMs, resulting in more aggressive and invasive tumors. In addition, certain environmental factors like hypoxia further enhance the expression of ICAM-1 in macrophages which is associated with more aggressive features of GBM.
CTNI-18. FIRST MULTICENTRIC REAL-LIFE EXPERIENCE WITH THE COMBINATION OF CCNU AND TEMOZOLOMIDE IN NEWLY DIAGNOSED MGMT PROMOTER METHYLATED IDH WILDTYPE GLIOBLASTOMA
Authors: Lazaros Lazaridis, Elisabeth Bumes, Dorothee Cäcilia Spille, Tim Schulz, Sina Heider, Sarina Agkatsev, Teresa Schmidt, Tobias Blau, Christoph Oster, Jonas Feldheim, Walter Stummer, Almuth Friederike Kessler, Clemens Seidel, Oliver Grauer, Peter Hau, Ulrich Sure, Kathy Keyvani, Ulrich Herrlinger, Christoph Kleinschnitz, Martin Stuschke, Ken Herrmann, Cornelius Deuschl, Stella Breuer, Elke Hattingen, Björn Scheffler, Sied Kebir, Martin Glas
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND The randomized phase 3 CeTeG/NOA-09 trial assessed whether CCNU plus temozolomide was superior to temozolomide alone in newly diagnosed MGMT promoter methylated glioblastoma patients. Survival was significantly improved from 31.4 months (temozolomide) to 48.1 months (CCNU plus temozolomide). In view of this encouraging data, we assessed safety and efficacy of this regimen under real-life conditions. METHODS We retrospectively collected clinical and radiographic data from adult newly diagnosed MGMT promoter methylated IDH wildtype glioblastoma patients from five neuro-oncology centers in Germany. For inclusion in our analysis, treatment with CCNU and temozolomide had to be performed for at least six weeks (one course). RESULTS Seventy patients were included. Median progression-free survival was 14.4 months and median overall survival 33.8 months. Patients with TTFields treatment for at least eight weeks and CCNU plus temozolomide (n = 22, 31%) had a prolonged progression-free survival compared to those with TTFields treatment for less than eight weeks (n = 48, 69%) (21.5 versus 11.2 months; p = 0.0105). In a multivariable Cox regression analysis, TTFields treatment for eight weeks or longer together with CCNU plus temozolomide and a Karnofsky performance score ≥ 90% were independent prognostic factors for progression-free and overall survival. Pseudoprogression occurred in n = 16 (33%) of investigated n = 49 (70%) patients. In n = 31 (44%) patients high-grade hematotoxicity was observed. CONCLUSIONS The results from this multicentric trial indicate - under real-life conditions - toxicity and survival estimates comparable to the CeTeG/NOA-09 trial. TTFields therapy for at least eight weeks in combination with this regimen was independently associated with prolonged survival.
Smoking is associated with infection risk in healthy blood donors
Authors: Bertram Kjerulff, Kathrine A. Kaspersen, Khoa M. Dinh, Jens Boldsen, Susan Mikkelsen, Lise T. Erikstrup, Erik Sørensen, Kaspar R. Nielsen, Mie T. Bruun, Henrik Hjalgrim, Ole B. Pedersen, Lise W. Thørner, Henrik Ullum, Sisse R. Ostrowski, Klaus Rostgaard, Carsten B. Pedersen, Torben Sigsgaard, Christian Erikstrup
Journal: Clinical Microbiology and Infection (2022)

<h2>Abstract</h2><h3>Objectives</h3> There is a gap in knowledge about the effects of smoking on overall infection risk in otherwise healthy populations, possibly leading to underestimation of the dangers of smoking. The present study aimed to examine the association of smoking with the risk of infections in a large cohort of healthy blood donors. <h3>Methods</h3> This cohort study used questionnaire and health register data from 127 831 Danish blood donors. Multivariable Cox proportional hazards analysis was applied to estimate the association of current smoking with the risk of all-cause infection defined as hospital-based treatment for infection or filled prescriptions of antimicrobials stratified for age and adjusted for relevant confounders. <h3>Results</h3> Among 18 272 current smokers, 12 272 filled an antimicrobial prescription and 2035 received hospital-based treatment for infections. Among 101 974 non-smokers, 65 117 filled a prescription and 8501 received hospital-based treatment for infections. Smokers had a higher risk of all-cause infection than non-smokers (hazard ratio estimates were 1.27 in males and 1.33 in females for hospital-based treatment and 1.11 in males and up to 1.20 in females for filled prescriptions). Smoking was most strongly associated with an increased incidence of respiratory tract infection, abscesses, skin infection, and prescriptions for these ailments (hazard ratio up to 2.29). Furthermore, smokers' risk of filled prescriptions of broad-spectrum penicillin was increased (hazard ratio up to 1.96). <h3>Conclusions</h3> Current smoking was strongly associated with the risk of hospital-based treatment of infection and filled prescriptions of antimicrobials in a large cohort of healthy individuals. These findings warrant an increased focus on infectious disease risk among smokers.
Tissue nanotransfection causes tumor regression by its effect on nanovesicle cargo that alters microenvironmental macrophage state
Authors: Gayle M. Gordillo, Poornachander Reddy Guda, Kanhaiya Singh, Ayan Biswas, Ahmed S. Abouhashem, Yashika Rustagi, Abhishek Sen, Manishekhar Kumar, Amitava Das, Subhadip Ghatak, Savita Khanna, Chandan K. Sen, Sashwati Roy
Journal: Molecular Therapy (2022)
Error in Open Access Status
Journal: JAMA Neurology (2022)

Ian J. Stewart, MD; Megan E. Amuan, MPH; Chen-Pin Wang, PhD; Eamonn Kennedy, PhD; Kimbra Kenney, MD; J. Kent Werner, MD, PhD; Kathleen F. Carlson, PhD; David F. Tate, PhD; Terri K. Pogoda, PhD; Clara E. Dismuke-Greer, PhD; W. Shea Wright, MD; Elisabeth A. Wilde, PhD; Mary Jo Pugh, PhD
Neuronal signal-regulatory protein alpha drives microglial phagocytosis by limiting microglial interaction with CD47 in the retina
Authors: Danye Jiang, Courtney A. Burger, Viktor Akhanov, Justine H. Liang, Robert D. Mackin, Nicholas E. Albrecht, Pilar Andrade, Dorothy P. Schafer, Melanie A. Samuel
Journal: Immunity (2022)